Turret injection machine



H. F. Ma-CMILLIN TURRET INJECTION MACHINE July 26, 1949.

6 Sheets-Sheet 1 m m M M M E D m M H,

INVENTOR E KN (R O T T A July 26, 1949.

H. F. MacMlLLlN TURRET INJECTION MACHINE 6 Sheets-Sheet 2 Filed J'uly 1,1944 :NVENTOR N UA N. M S Y c E Mik/m n #m D: m M M H July 26, 1949. H.F. M'acMlLLlN 2,477,258

TURRET INJECTION MACHINE Filed July 1, 1944 s sheets-sheet 5 65 l @i1-Ef lNvENToR A Howakn E Mao/"lum,

ATTORNEYS July 26, 1949.r H. F. MacMlLLlN TURRET INJECTIONA MACHINE 6sheets-sheet 4 Filed July 1, 1944 INVENTOR Howmm E MAcMmm,

July 26, 1949. H. F.. MacMiLLlN 2,477,258

TURRET INJECTION MACHINE Filed July 1, 1944 e sheets-sheet 5 INVENTOR.HOWARD EMAC. MILLIN, BY ,l l m i ATTORNEYS July 26, 1949. H. F.|v|olvn| l lr-1v 2,477,253

TURRET INJECTION MACHINE Filed July 1v, 1944 e sheets-sheet eV lNvENToRHowARo EMMMILUN, BY

M1 ATTCRN EYS Patented July 26,41949 UNITED PATENT OFFICE l .Meeuwis yHowardRjMacll/Iillin, Mount Gilead', ,Ohio, assignor -to 'H-'P-MDevelopment'Corporaton,

Wilmington, DeL, incorporation of Delaware application July 1, 1944,seriaiNasianv Y "27 Claims. (CLIS-30) 1 Y 1 This invention relates toinjection machines for injecting plastic materials.

object of theinvention is to provide an injection machine whereintheplast-ic material is fecgirismcasured, charges .into o preccmprcssionchamber for forming pellets of A*plastic`A material that aresubsequently transferred to a turretand carriedthrough a heating stationand-thence to an injection station wherein the heated'plastic pellet isremoved fromtheturret and transferred to Ianinjection chamber forejection therefrom by an injection plunger.

Another object ofthe invention is to provide a plastic injection machinefor compressing piasti material into the formof pellets and. ejectingtheplastic material :from an injection chamber after being suitably`heated` at an intermediate statiomwhich machine 'includes a turret forcarrying theplastie pellet from the precompressing station to theinjection station and wherein pthe pressure developed onthe plasticmaterial for precompressing and ejecting thesame is carried out in,chambers separate from` the turret ,so that the turret is not requiredtobe constructelto withstand 'high pressures.

' Another obj ectA of the invention is ,to provide lan injection`machine wherein plastic material is heategi in :chambers carried inatlllret 'by means of high frequency criereyfwhich heated material canbe subsequently moved vto anfinjection station immediately" after beingheated for, ejection from an injection chamber.

y"Still another ob'jectof the invention 'is to provigle injectionymachine in aceorlarice` with the Jforegoing object wherein thetur'ret5can "be constrlgicteg1` of electrical insulating materialstopermit r'heating loi-gthe plastic materialhin the chambers vinA theturret, the chambers in .tne turretalso being colistructedvofelectricsal insulatingmaterial.

Still another object Voi Vthe ,inventionA is to pro.-

videfaninjection machine Ain accorglaiicel with the two foregoingobjects wherein the jplastic material Vis pre-compressed into pelletform i n aehambeij separa-te from the turret and is ejectegl from-'aninjection chamber :that is separate from theturret se that thevelectrical insulating materials from lwhich the turret iis constructedare not required to withstand( high pressures.

HAStill another object oi the inveniion'is 'toprovide'ean lirijec-ionYmachinehaving ajturret for cciivcviheolestic ,materiel 'from ailoaciinastationfto -a heatingstation, and subsequently-@ injectionstation wherein the plasticmaterial is heated -while l disposejil v:inthe turret for gsubse- 2 quent .transmittaltc en injection station'aiidejection therefrom.

Still ariothecobiect ci the invention .is to provice Aarimisectionlmachine in accordance. with the foregoing objects whereinthe'turret maybe constructies from plastic materials- Siiiiaiiotherobject. oi the invention is to pro-V vide an injection machine inaccordance with o f theforeeoihe objects. wherein the operationsoipre-compressing plastic material and heating, ,plastic material. ereperiormedvsiihstantially concomitantly irornseparate stations, and theoperations ci hlacineaprefcoihnressed .charge of. plastic materialiniotthe turret and .electing hestedcharse o f; plastic material areperformed independent, stations substantially concomitehcly butalternately .with the first-mentioned Operations.

. A furtherobject. o f .the invention is to provide a clasticinieciioii.machine ,in accordance with theioieeoirls objects wherein the variousoperations nerforihecihy .the machine .are carried ont aiitoinaticallvbya suitable control system.

'Furtherobiccts andadvantaees will become .ap-

- parent. irom .the `cravviiies .and theliollowine. .de-

sciiptiori.

p In the., drawings:

lis, general, .a vertical cross-sectional View .of theanparatus of thisinvention, but e part of the mecha ism is shownin elevation..

Figure 2 is..p1ai,1 view of theapparatus shown ihgiigure .1 r/:ith aportion thereof shown in cross.- Scctiones takenalone Enel-2 of Figure1.

Figure 3 is a horizontal cross-sectional .View

thronsh theyre-.compressing mechanism .of the apparatus, .as taken.alone line 3-3 .of .Figure ;1

;Eigiire elvis ,anonlarged crossesecti-onal vviewv illustratinglthe`arr-ai inem ent Eof the high `freF quencvheatihe .apparatus for theplastic meierialthat isrcarried/ih the .chambers .of the turret.

.Figure 15...is.ari..end .elevational view of the machine.. of\this.inventi on as z.viewed from vthe night-hand endi-the machineas shownin Figllrcl.

. Heure 6. ,is-.a cross-sectionalview of `the indexing latch-boltmechanism for the turret of ,the

machine Vischen ,substantially -along' line `6-.6-` oi Figure Elgu 7.15ai @91120111931 Cross-sectionalwiew through .a modified. structure ofthe. injection chamber 4 that is .associated with .the turret oi ,themachinefigure 8 is a rerticelcrossfsectional view-of Figure 9 i-s ahorizontal cross-sectional view of the machine shown in Figure 8 and istaken along line 9 9 of Figure 8.

Figure 10 is a partial cross-sectional view illustrating the associationof the electrode elements for heating plastic material contained in theturret chambers.

Figure l1 is a partial cross-sectional View of the turret of theapparatus shown in Figure 12 illustrating a modified electrodearrangement for heating plastic material in the turret chambers.

Figure 12 is a side-.view of a modied arrangement of apparatus relativeto the manner in which the turret is associated with the other elementsof the machine.

Figure 13 is a cross-sectional view of a part of the turret illustratedin Figure 12 showing the positioning of the electrodes for heating theplastic material in the turret chambers.

Figure 14 is a diagrammatic view showing a hydraulic system foroperating the machine disclosed in Figures 1 and 2.

Figure 15 is a cross-sectional view showing a modied arrangement of theinjection chamber of the Vinjection machine.

Figure 16 is a simplified schematic wiring diagram of the control systemfor operating the injection machine automatically.

Figure 17 is a cross-sectional View of the turret of the injectionmachine showing an arrangement thereof that is a modified structure fromthat disclosed in Figures 1 and 4.

In this invention, the injection machine as illustrated in Figures 1 to6 inclusive, consists of a bed I9 having a bolster Il secured theretothat carries a stationary die i 2. A movable die I3 co-operates with thedie I2 so that suitable mold cavities can be provided therebetween. Themovable die I3 is carried upon the die plate I4 supported on the ram I5that is reciprocated by the hydraulic motor I6. Strain-rods I1 extendbetween the bolster I8, that supports the hydraulic motor IG, and thebol-ster II whereby to receive the force of holding the dies I2 and I3together. The die plate I4 is slidable upon the strain-rods I'I forguiding movement thereof.

The bolster II has an opening I9 therein that receives an injectionchamber 29 having the internal cylinder bore 2|. Y The injection chamber29 is suitably secured to the bolster I I.

An injection plunger 22 has a piston-head 23 on one end thereof thatreciprocates in the cylinder 24 whereby to provide a hydraulic motor 25for reciprocating the plunger 22 within the injection cylinder in amanner hereinafter described. The cylinder 24 ha-s a ange 2S that isengaged by the strain-rods 21 to thereby support the hydraulic motor 25from the bolster I I.

A turret 39 is rotatably mounted upon the supporting shaft 3I carriedbetween the bolster Il and the flange 26 on the hydraulic motor 25, thusplacing the turret 39 between the injection chamber 29 and the hydraulicmotor 25 so that the injection plunger 22 must pass through the turret39 before entering the injection cylinder bore 2I.

The turret 39 is preferably constructed from a pair of side plates 32that are spaced from one another by the shoulder 33 provided on thepivot bushing bearing 34 of the turret 39. The side plates 32 areprovided with a plurality of chambers 35 positioned therebetween andspaced equidistantly around the turret 39 so that a chamber 35 ispositioned every 99 degrees around the turret.

The side plates 32 that form the walls of the turret are preferablyconstructed from electrical insulating material, and can be of plasticmaterial, because as hereinafter described, the turret is not requiredto withstand any pressure relative to the operating conditions of themachine. Also, the turret chambers 35 are constructed of electricalinsulating. material, and can be of plastic material, for the foregoingreason. Also, it is preferable to construct the side plates 32 and thechambers 35 of electrical insulating material because the plasticmaterial that is contained within the bore of the chambers 35 is to beheated by the use of high frequency energy in a manner hereinafterdescribed. However, it is not to be considered that plastic materialsalone are used in the construction of the turret 39, but rather metalscan be used regardless of the type of heating that is applied upon theplastic material in the turret chambers 35, including the use of highfrequency energy. Also, as illustrated in Figure 17, 'the turret 39 maybe constructed withmetal side plates 32a which carry the chambers 35aconstructed from electrical insulating or plastic material such asStyrene which will not heat when in the inuence of high frequency energyand which may be of sufficient strength to withstand high pressures topermit compressing plastic material therein and ejecting the sametherefrom. The metal walls of the turret 39 are preferably groundedrelative to the circuit from the high frequency generator whereby theintensity of the eld of high frequency energy within thematerial-receiving chamber 35 is increased because the body of groundedmetal in the turret prevents stray radiation of the high frequencyenergy.

The turret 39 is indexed by an electric motor 49 having a sprocket-wheelon the shaft thereof that drives a sprocket-chain 38 in engagement withthe sprocket-wheel 39 provided on the turret bearing bushing 34.

Y A bolt-latch mechanism is provided for locating the turret in properposition upon each indexing movement thereof and consists of a solenoidS3 that operates a latching-pin 4I for moving the same into apin-receiving bushing 42 that is provided between the turret plates 32.A spring 43 retracts the latching-pin 4l from the pin bushing 42 whenthe solenoid S3 is deenergized.

The turret 39, as rotatably supported upon the pivot shaft 3|, is sopositioned relative to the injection plunger 22 and the injectioncylinder 29.

that the turret chambers 35 are positioned in vertical and horizontalarrangements 90 degrees apart when one ofthe chambers 35 aligns with theinjection chamber 29.

Mounted upon the bolster I l there is provided a cylinder 45 having apiston 46 therein that carries a ram reciprocable through the turretchambers 35 when-hydraulicfluid is supplied alternately to oppositesides'of the piston 46 in the cylinder 45. A cylinder 59 is supported bythe strain-rods 5I between the flange 52 on the cylinder 45 and theflange 53 on the cylinder 59. The cylinder 59 forms a hydraulic motorthat has the piston 54 therein reciprocable in the cylinder 50 uponthe-application of hydraulic luid to opposite sides ofthe piston 54. Thepiston 54 has a ram 55 extending therefrom and reciprocable through theturret chamber- 35 in a manner hereinafter described.

Afeed chamber E9 is positioned between the turret 39 and the cylinder59, and has a cham- 7 the plastic material in the feeding chamber 60, asheretofore described, high frequency current is supplied to theelectrodes 6B and 66a. that are now in engagement with the plasticmaterial in the turret chamber 35 at station A to thereby heat theplastic material to a suitable temperature for ejection from theinjection cylinder when the turret is indexed upon the next operation ofthe machine. However, before the turret is indexed, hydraulic iiuid issupplied to the right-hand side of the hydraulic motor to retract theram 4l to the position illustrated in Figure 1, and simultaneouslytherewith pressure is relieved from the right-hand side of the hydraulicmotor to prevent any further forward movement of the ram at this time.

The turret 30' is then indexed by operation of the motor 50, thelatch-bolt 4| being withdrawn from the latch bushing 42 by operation ofthe solenoid S3. When the turret begins rotation, the solenoid S3 may bede-energized to permit the latch-bolt to ride upon the surface of theturret 30 and thus permit the same to drop into the next latch bushing42 that is 90 degrees of rotation away from the same.

When the turret 30 stops its indexing motion, it has rotated 90 degrees,thus placing the heated charge of plastic material, heated at thestation A, into alignment with the injection cylinder 20 at the stationB.

Hydraulic iluid is then supplied to the righthand side of the hydraulicmotor 25 to advance the injection ram 22 through the turret chamber 35at station B and thus transfer the heated charge of plastic materialfrom the turret chamber 35 into the injection cylinder 2Q. The ram 22continues its forward movement to eject the plastic material from theinjection cylinder 20.

Concomitant with supplying hydraulic fluid to the hydraulic motor 25,hydraulic fluid is also supplied to the hydraulic motor 50, on theright-hand end thereof, to again advance the ram 55 to transfer thepreviously pre-compressed pellet of plastic material from the feedingchamber into the turret chamber 35 at station C.

After the injection ram 22 has completed its forward movement to fillthe molds or dies l2 and I3, hydraulic fluid is supplied to the lefthandends of the hydraulic motors 25 and 58 to retract the rams 22 and 55,respectively, into the positions illustrated in Figure l.

When the ram 55 is retracted, the motor 65 for the feed screw B4 can beoperated for a predetermined time to feed a predetermined quantity ofplastic material into the feeding chamber 60. Also, with the ram 22removed from the turret chamber 35 at station B, theY turret 3B canagain be indexed 90 degrees so as to place the pellet now retained inthe chamber 35 at station C into position forheating at station A,whereupon another charge of plastic material can be pre-compressed inthe feeding chamber 60 when the turret stops its indexing motion in themanner heretofore described.

It will thus be seen that the machine of this invention is capable ofpre-compressing measured charges of plastic material in a chamberseparate from the turret that are subsequently transferred into theturret so that the turret can carry the pre-compressed charge of plasticmaterial through a heating station, wherein it is heated, to aninjection station, wherein the heated plastic material is transferred toan injection chamber and ejected therefrom. The turret is therefore atno time subjective to high internal pressures, and therefore can beconstructed of relatively light-weight materials, or plastic materials.

In Figure 7 there is illustrated a modified structural arrangementbetween an injection cylinder and a mold-part that is associatedtherewith, whereby the mold-part can be separated from the injectioncylinder when the molds are open to break the sprue between theinjection cylinder and the mold and to prevent transfer of heat from theinjection cylinder to the mold. In this arrangement, the mold part ordie I3a is supported and operated in the same manner as the mold-part ordie I3 heretofore described.

The mold-part, or die |2a is carried upon a plate IDI that is supportedby the pins |02 extending from the bolster IIa.. Springs |03 arepositioned between the bolster IIa and the plate |02 to normallyposition the plate in spaced relationship relative to the bolster I Ia.

The bolster IIa carries an injection cylinder |04 that has an injectionchamber I therein and heating passages |06 surrounding the chamber |05.The forward end of the injection cylinder |04 is provided with aninjection nozzle |91 that has a nozzle orifice |08 through which theplastic material is transferred into the mold cavity provided betweenthe mold-parts, or dies |3a and |2a.

When the mold-parts I2a and |3ar are open, as illustrated in Figure 7,the mold-part |2a is spaced from the nozzle lill1 to thereby preventheat transfer from the injection cylinder |04 through the nozzle |01 tothe mold-part IZa. Also, this separate movement breaks the sprue whenthe molds are opened.

The turret 30 can be constructed and operated with regard to theremaining parts of the machine illustrated in Figure 1 in the samemanner as vheretofore described.

In Figures l1, 12 and 13 there is illustrated a slightly modiedarrangement of the machine of this invention wherein the chambers in theturret are adapted to receive molding powder without firstpre-compressing the same so that the molding powder can be carried fromthe feeding station through a heating station to an injection station.

In the arrangement shown more specifically in Figure 12, the apparatusconsists of a bolster Ib carried by the frame Ib. An injection cylinder20h is carried in the bolster IIb and co-opcrates with a mold or die|2b. A turret 30h is rotatably mounted above the injection cylinder 20hupon the support shaft SIb, and consists of the turret plates 32h and aplurality of individual turret chambers 35h, all in the same manner asheretofore described.

A hydraulic motor 25h having a ram 22h is associated with the turret3019 as is the hydraulic motor 50h having the ram 55h for respectivelyejecting plastic material from the injection cylinder 20h and fortransferring plastic material from the feeding chamber -SIlb into theturret chamber 35h in the same manner as heretofore described.

The plates IGS and ||0 are positioned adjacent opposite faces of theturret 30 to engage the turret plates 32h, whereby the turret rotatesbetween the plates |09 and IIB in constant engagement therewith. Theplate IIU is provided with an opening therein which aligns with the feedchamber 60 to permit transfer of plastic material from the feed chamber60 into a. turret chamber 35 when in alignment with the feed chamber 60.The plates |09 and III) are provided with suitable:openingsmheneinewhiclr alien. the injection ram 22h to permit it to passthroughithe turret. i and :en-ter:A fthe; ineetiouxcylinder. f 2.011. or.ej eating. plasticLv materiallfronn the-.ini ection cylinderaftertransferrmg-.the plastic.: material ,from ltheturretiintofthe-injectionfcylinden f, There are no other :openingsvprovided'- in the V:plates .|09 and I l0, thus when powdered orgranular-...plastic ma.- teria-luis' iedfv 4fromztlne.hopper.. 63hintc.the feed chamberfb by the mot-M1651);h the'fpowdered. or granular -.plastic V materiali being subsequently transferred vinto l turret .chamber3511; the. fpow. dered. or granular? vplastic material can .thenl be.carriednby theturret between the plat-es .|93 and f from .the feeding.stationzthrougla .the; hea-,ting. station- A and v.tothe..injectionstation C in the .manne-r .as heretofore describedzu At.the heatingfstation A, the electrodeplates are preferably-.imbedded::inthe; plates '|03 `and H0. -The plastic-material .in theiturretfchamber35D is thus carri-edfbetween-the .electrode plates I and:-|.|2- ior.-heating by thefdfngn-irequency field lestablished '.between theelectrode; @lates that l are 2 suitably..cpnnected. to a; high':frequency .generating-.unites f The v.plates-|1151 .andi M0.:.arefspreferablyz con- -structed .ci .electrical insulating material, orplasj- -tic .mater-iaL-.er the fportionthereof'.thaty receivesthefelectrode plates li l. .fand:.|'|2 maybe `electrically.insulatedrffromsthe i remaining; .portion of theplagtesatll!!` and M02As a further fmodifled 'arrangementroi the manner ofapplyingmheshigh-frequency.field'. to the.-.plastid-material-.-.containfed ein the #turret chamber 13511;.Eigureall discloseszfan arrangement whereinthoelectrodes J,-|.3-and 1Marcin the term of ringseinserteddn the; endwallsniof .the turretchambers. 35hl fT-hesee electrQdeVriHgs-.Ii3, ,|14 are engagedbyspringspressed.contactors-| .|5f, -IfI-S whendthe turret `chambers` 351iareI disposedV in positionat the-heatingistationf.

. In Figure-S :and Btheresisillustratedza modified arrangement .ot the.injection machine.*ofI this. invention wherein the turret isdisposed-.horizontally and .measured .chargesof plasticv.materia-lcan befed into theturrethambers thrcugh-the-open ends. thereof.

The machine.consists..of .a bed .|20..havingt=a cylinder |21|v formedthereinto .provide .vaecyli-nder chamber. |22. that receivesapiston`l22e-fm...'f-.heref "i by forming a hydrauldmotor... lThe.pister-1.1.428 haga ram. .|24 .extendingrom the.cy1.inder |.2| that-supports a.mold-carrying..plate..-|25 .which in .turn carries .a moldparti 2li.

The head |21 0f the injection machine is suite ably connected tothebeddl by means of strainrods |28, I some. .of the...strainfrods...extending through. the mold..carrying plate. |25 to guidethe same4 upon .movement thereon-...A :stationary mold-part. |291 is.carried upon thahe'ad .of thema.-

chine |21', and an. injectiomcylindenl .is secured to the head1'l1.'r

A turret .|35 is mounted ...upon..,the- .Shatifjl thatissuitablyjournaled .in the inedJZ andthe head |21 of the..injectinn..rnachine, i. The .shaft 13| carries. a worm.wheel.l32..nntheuppelbend thereof that is driven by awormlacarriedlupon the shaft .of -the electric. motor .134. to .thereby rotate.the turret |35....

The turret. .|35 consists of the.. two .sdeepla-tes |36 that receiveturret chambersillipositioned therebetweenfior holdingfcharges .of.plastic material. .These....turret. .chambers |31. vare. spaced aboutthe turret |35 .in thefsame mannenas here,- Vtofore. .described .with.regard ,to .the-.turret .3D .il-

lustrated in Eigurerl.; -fThe turret. |35.. engages: y a plate. |f38 toretain.'theschargesxof granular or powdered plastic material fin theturret chambers |31 when moving the same from the feedingstaf tion t0vthe injection-.station.e

A hydraulicemoton-M has a. piston |4| reciprrocating. inthecylinderv-MZ. end to which the injection ram.- l.3.9ia attached,which reciprocates through the. turret chambers 31 to transfer plas-.tic material. fromthe .same into the injection .cylinder andfte eject-rplastic. .materialv therefrom.

A .reed hopper-.54143.4 is secured to the headw|21 by fthe. bracket dit,y. vand has a Afeed-vllhcel 14.5 therein driven by -anclectr-ic motor|46.. The electrimmotorwlll; is. controlledby suitable con.-trollingvdevicesto rotate .the y.feed-Wheel in vsuch .a .mannekes .to.emptyonly. one section of the feed-whoel-'at .a time, gthe sectionsofthe feed- Wheel -fbei-ng; provided. -by .the vpartition .Y members Theturret 4.35,l is positioned, after. an .indexing motiemfbytheJatch-.bolt 1.48 `that. entersffthe `bushings |429- afterfeachindexingxmotion.- The latent-.bolt .'l contrclledmby .a solenoid. |50which .withdraws theelatchfbolt from the rturret when:v einergizedae-The turret; |35 is prqvidedzwith a. feeding station, .and @wheat/ingvsl'.a.tien .ar1d .an .injection staetion..;similar .to the.arrangementl .disclosed with .regard :to the turret;y 3.0 .showinfanddescribed in Figure-.1, The Yheating'station-jor the turret V|35includes aan .elect-rode`v member ..15 that z .ma-y. i be imbeddeddnthe'fplate,:|38.f..A second electrode |52 scarried upon' the .end of aplunger |53.. act.u

to enter the turret chamber |31 Whenthe solenoid Lrisenelgzed. Theelectrodes Y|.5|.,.I52 are vconnecte d. -.to ai suitable: source:- oihigh frequency .currentaori producing a. field-cf high `frequency energybetween-thepfelectrodea .and thus.. vheating the. fplastie material in.the turret. chamber 31.

The v'operationof thev apparatus-shownin Fig.- ures 8 and 9 is similarin all .respects te the opera.- tion ai, theapparatusdisclosedinFigur-estaria 2 :with the .exception- =that .the preecempressionopyeratiomin? "the plastic.material is dispensed. with .andthe-plasticfmaterialis thus.. retained-.;in the turret chambers .|31 .in:ai powdered-or granular -fcrmfdurineithecycleef operation .of themachine. Figune.. 15 .illustrates A.a modified.. arrangement ofthoinjection-apparatus wherein themoldfparts .l 55.and...|-56;cooperateto form. a ,mold cavity |51..injection.cylinder...|58 ,has the .end .thereof insertedabetllvecln..the;.Kleid-partsI .|55 v`21nd |55 alongthe martine-...line|59 .thereof The Lturret |50, previously. described is disposed:adjacent .the injection .cylinder z |58 An. injection plungera-I- I..Apassesthrough .the .turret Mill: .to ttransf-e1' pasticmateralrfrom the.turret intothe injection. .cylinder V.|58pfand. to :eject .the plastic.materialf-rom .the :injection-cylinder.. A mold- .clamping ram.lzretans the .mold-parts` and |56. ,togethen during.. the...injectonoperation.. Y

The electric controls ,for .operating the.. iniecr `tion.-macl-iine..illustrated in Figures. .1. to .6; .inclusive, consistspitheaforementioned .electric con@ trois described.. when referring .to,the .detailed .descriptionbi the machine.. and in addition consists4 ofthedimit. switch .LSaengaged by the .cam |55. on ftheturret. `3l] vjus\t.beiore thev rturret completes its indexing .mctiomend the .limitswitches L55 @and .LSt-that aref. alternately engaged .by the .camsJzontheiturret. 30 .upon each 90 .degrees .of dictation. of .the,.turret..to `select the. cycle. .of .operation QI the. machine. .in .amannerherein.-

1l after described. In addition, there is provided a limit switch LS1engaged by the ram 55 of the hydraulic motor l! when it is in fullretracted position.

Figure 16 illustrates a schematic Wiring diagram for electricallyinterconnecting the various control elements for the machine, all efwhich devices are connected to the power lines X and Y. To start theoperation of the machine the `starting switch |61 is closed, whichcauses energization of a contacter A, the limit switch LSs in thiscircuit being closed at this time. Energizing contacter A closescontacts A1 and Az to establish a holding circuit for contacter Athrough contacts A1. Contacts A2 establish a circuit through the latchsolenoid S3 to energize the same and withdraw the latch-bolt from theturret. This operation will occur if the pelleting ram is in its fullretracted position to close the limit switch LS1.

Energiaing the latch-belt solenoid S3 causes movement of the bolt 4| tostrike the limit switch L82, which limit switch establishes a circuitthrough the electric motor d0 to begin indexing of the turret 36. Whenthe turret approaches the end of a QO-degree indexing motion, limitswitch LSB will be engaged by the cam to open the same and therebycle-energize contacter A which opens contacts A1 and A2 to break theholding circuit through the contacter A and the circuit L turret untilthe latch bolt 4l drops into the next latch opening.

When the latch-bolt 4I drops into the next latch opening, whichindicates a QO-degree index of the turret 30, limit switch LS1 isclosed, which limit switch, as indicated in Figure 16, is provided withdouble contacts to cause energizatien of two parts of the circuit asselected by the limit switches L and LS.

Assuming that limit switch LSs is engaged by a cam 166 to close the sameupon completion of the turret indexing, the closing of limit Switch LS4will thereby energize contacter B to close centacts B1 and B2 andinitiate the rst phase of the cycle of the operation of the press thatincludes pelleting or compressing of the plastic material and heating ofa charge of plastic material.

Closing of contacts B1 forms a holding circuit for contacter B whileclosing of contacts Bc establishes a circuit through the solenoids S1and S2 operating the 4-Way valves 80 and 8| to advance the rams 41 and55 toward one another to compress a pellet or charge of plastic materialin the feeding chamber 60. Simultaneously therewith, solenoids S7 and Seare energized to place the electrodes 66 and 66a in engagement with thecharge of plastic material that is contained in the material-receivingchamber 3'5 at station A of the turret to heat the plastic materialtherein.

When contacts B2 were closed, a timer T started its cycle of operationto time the heating cycle of the plastic material. As soon as the timerT runs its cycle, contacts T1 are closed to again initiate energizationof contacter A to actuate the latch solenoid S3. However, when contacterA is energized, contacts A3 are opened to de-energize contaeter B andthus (le-energize solenoids S1, S2, Sv and S8 te stop the heating cycleand retract the rams 47 and 55. As soon as the ram 55 reaches the end ofits retraction stroke, limit switch LS1 is 'closed to permit completionof the circuit through 12 the latch solenoid S3 and thereby retract thelatch bolt 4l.

yAs soon as latch-bolt 4I is retracted, limit switch LS2 is closed toagain initiate operation of the indexing'moterr 40 to index the turret90 degrees. As the turret indexes, limit switch LS1 is again closed whenthe latch-bolt 4| drops inte the next latch-bolt opening.

At this time the turret will have indexed degrees so that the cam |66aWill new contact limit switch LS1; to initiate the second phase of thecycle of operation of the machine thatincludes injection of the plasticmaterial from a chamber in the turret and insertion of the previouslypre-compressed charge of plastic material. When limit switch LSG isclosed a circuit is made through contacter C. Contacts C1 form a holdingcircuit for contacter C, while contacts C2 form a. circuit through thesolenoid S4 to cause operation of the hydraulic motor I6 to close themold and clamp the same upon the stationary mold.

Simultaneously with closing of contacts C1 and C2, contacts C3 areclosed and contacts C4 are opened. Closing of contacts C3 establishes acircuit through solenoid S2 to again initiate operation of hydraulicmotor 50 to cause insertion ef the previously precompressed pellet intoa turret chamber. Contacts C4 are opened to de-energize the circuits tosolenoids S1, S1 and Sa to prevent operation of the hydraulic motor 45and the solenoids S1 and Ss for the electrodes 66 and 66a..

When the hydraulic motor I6 closes the molds the tonnage control TC1closes a circuit through a contacter D when a predetermined pressure isreached in the hydraulic meter I6 te close contacts D1 and D2. Closingcontacts D1 establishes a holding circuit through contacter D andclosing contacts D2 establishes a circuit through solenoid S5 to operatethe 4-Way valve 19 and begin operation of the hydraulic motor 25 to movethe injection plunger 22 through the turret 3|) te transfer plasticmaterial from the turret chamber into the injection cylinder and ejectthe plastic material therefrom.

The injection plunger 22 moves forward until a predetermined pressure isreached in the hydraulic motor 25, at which time tonnage control TC2closes a circuit through contacter E that closes contacts E1 and Ez.Closing the contacts E1 establishes a holding circuit through contacterE While closing contacts Ez establishes a circuit through a timer T2 fortiming the completion of the injection cycle and the time at which theinjection plunger shall be retracted and the molds opened.

As timer T2 runs its cycle, contacts T23 are opened therebyde-energizing contacter D to open contacts D1 and D2 to de-energizesolenoid Ss and thereby permit the 4-way valve 19 to be returned toitsinitial position to place the hydraulic motor 25 on a retraction stroke.

Subsequently, timer T2 opens contacts Ta thereby de-energizing contacterC to open contacts C1 and C2 which de-energize solenoid S4 to permit the4-Way control valve '18 to return to its normal position and cause thehydraulic motor I6 to retract and open the molds.

Subsequently, contacts T21; are closed to again establish a circuitthrough contacter A and reinitiate an automatic c-ycle of operation ofthe injection machine.

A selector` switch |68 is provided for selecting between automatic orsemi-automatic operation of the machine. If the switch |68 is closed themachine will operate on an automatic cycle of bers, saidmaterial-receiving chambers said yacercara 13 operation, and. if open',iwilli operate' Vorrfa semi'- automatic cycle of operation.

While.: the apparatus disclosed and described herein constitutes apreferred form 'ot the invern tion, yet Vmodifications oi the apparatuscan be made withoutv departing from the-spirit" of the invention, andall modiiicationsthat tall` v1within the. scope of the-'appended claimsare intended to be included herein.-

Having thus fully described myinventicn'r,I what I claim as new anddesire, to secure byiietters Patent is:

l. A turret injection machine'thatincludes-in combination, an injectioncylinder"I providingan injection' station, a plastic material *feedingmechanism providing,- afeeding station, 'arot'at-A ably mounted turrethaving a pluraiity'of un# heated material-receiving chambers' thereinconstructed of electrical insulating materia-I, means rotatably mountingsaid turret-for' rotation-betweenzsaidI injection station andsaidieedi'ng station to provide for movement of saidchambers frornthefeeding station to the: injection'fstation; means for `intermittentlyrotating said turret'to place said chambers at said stations,aninject'ion plunger Vmovable through saidl materialereccivine chambersin said' turret to transfer-'plastic material'therefrom into'saidlinjection cylinder,` and electrode means positioned in alignmentonoppo siteE sides of the turret for establishing a; heid oi highfrequency energy/within said? lvmaterial#rreceiving chambers inv saidturret when said chambers are in a 'stationary position between thefeeding station and the injection statioi'i.

2. 'A turret injection mach-inethat includes in saidchanrbers are in astationaryposition'to thereby provide a heating.station.v

3.. A turret irrjectionmachine.- that includes' in combination. aninjection cylinder-forming an: in: ject-ionl station andhavin'g' an:--injection 'plunger associated: therewitlrga turret' rotatably mountedadjacent saidinjection cylinderandfhaving'aplu: raiity: of 1unhea-tedinaterial'reeeivingvchambers thereinya feeding mechanism for 'feeding'-plas# tic material into said maierialreceiving."

turret being` constructed of electrical-Tf insulating material, and.electrode' means positioned a ment on. opposite sides of the turret'forproducirre a eld of high frequency energy withinsaidmaterial-receivingfchambers to heat plastic-.material therein, sai'dfYheating' means 'losing-` 'etatienarily positioned laci-jacent theperiphery ofi thetur-ret atay point substantially mid-way' 'between-`'the location' of. the feeding. mechanism. andthc inljection cylinder..

4. A turret injection machinethatl includesfin combination, an injectioncylinder', aturretrotai ablyV mounted adjacent said injectioncylinderand including a plurality 'of unheated mate ali receiving chamberstherein forl seo'uentiali-lien?-YV ment f with -saidi Ainjection Ycylinder', 'said materiallreceiving chambers in turret beine con;structedfof electrical insulating nraterialyan injection plunger movablethrough said materialreceiving'lr-charnbers to trans-ferplasticlmaterial from the vchambers into thev injtectioncylind'erwithoutL-placinghthef chambers under any substantiat pressure', afeeding mechanism for feeding: plastic. material-*into sai-dmaterial-receiving chambers;:and: electrode means disposed adjacentoppositet endsof one'of :thermateriahreceiying chambers-and adapted tobe connected to a source ci vhiglrlireduf-:ncy currentwhen other oi.said material-receiving `chambers are stationarily positioned inoperative position adjacent the feed; ing; vmeans and rthe injectingmeans-to thereby lfieat'rthe.3 plastic material in themateriale-receivingV chambers before --transfer thereof iromthematerial-receiving chambers into the injection cylinderby saidfinjectionplunger; y

5.. A- turret injection machine that includesin combirration,anyinjection cylinder,V a turret rotatablymounted adjacent said injectioncylinder andv-includinaa plurality of. material-receivingr chamberstherein ior sequential. alignment with said:J 2injectioncylinder,` said-Vmate-rial -receiving chambers said; tur-retbeing constructed ofelectrical-A insulatingmateriaL an injection plunger movablethroughfsaid materialreceiving chambers to tran-sier plastic materialfrom the chambers. linto: the injectionV cylinder without placinathechambers underany substantial pressure; ya feeding mechanism forfeeding. plastic materially into said material-receiving chambers,electrode means disposed adjacent opposite ends ci lorre'oi thevmaterial-receiving -chambers and adapted to bey connected to a source ofhigh-frequency' current-when other of saidlmaterial-receiyi-nafcharnbersare Stationarifly positioned inoperativexposition. adjacent the feedingmeans ari-'dihe-V injectingrneansto thereby heat the plastiomaterial-in the material-receivingchambers before transfer thereof from thematerialreceiving:chambers-into injection `cylinder by saidinjectionplunger, and an. indexing mechanisnrfor -seduentiallyirrdexing saidturret-*to selecte'dwstationarypositions to placel the ima#teriedereceiy'ing chambers sequentially in position toV receiveplastiematerial from the feed-ing mechanism, 'in position for causingestablishment of theihigfhfrequency'eld within .thematerialreeeiifingxchambersfor' heating the material, and in postion'in:alignment with the injection cylinderr'fanda-the plunger associatedtherewith for transfer ofthej plastic-material into the-injectioncylinder-H y 6e A tuifretf injectionma'chine that includes incombinatiomran injection cylinder AproVidin-giarr injection station-afeeding` ychamber providing a feeding-fstati'on-a turret having apluralityof materialereceiving chambers'- `therein androtatablyfdisposedf between 'saidinj ection cylinderV and said'iced-ine:l chamber to. transfer plastic; material yfrom: the 'Lieedingzchamber: to the injection cylinder,- pliinger means for: compressingplastic matrialiste said feeding.' ehamb'er'and for' trans:- ferrinefthe'compressedmaterial into said materiallreceivingl;f-chambers iin.'saidturret', and nimeer.; meansassociad with said injection for'vtransferidas plastic materialfrom saidi materialei'receiiiina"chambrsfinsaid turret into saidi injection'cyl-inder andi to eject plasticmaterial! therefrom,

i.. A turret'inj" ation machine that includesoombinationi aie-#injectioncylinder providing an injection station, a feeding chamber providing afeeding station, a turret having a plurality of material-receivingchambers therein and rotatably disposed between said injection cylinderand said feeding chamber to transfer plastic mate- :rial from thefeeding chamber to the injection cylinder, plunger means for compressingplastic material in said feeding chamber and for transferring thecompressed material into said material-receiving chambers in saidturret, and plunger means associated with said injection cylinder fortransferring plastic material from said material-receiving chambers insaid turret into said injection cylinder and to eject plastic materialtherefrom, both ofv the said plunger means being movable through thematerialreceiving chambers in said turret to produce pressure upon theplastic material externally of the turret.

8. A turret injection machine that includes in combination, an injectioncylinder providing an injection station, a feeding chamber providing afeeding station, a turret having a plurality of material-receivingchambers therein and rotatably disposed between said injection cylinderand said feeding chamber to transfer plastic material from the feedingchamber to the injection cylinder, a plunger means for compressingplastic material in said feeding chamber and for transferring thecompressed material into said material-receiving chambers in saidturret, plunger means associated with said injection cylinder fortransferring plastic material from said material-receiving chambers insaid turret into said injection cylinder and to eject plastic materialtherefrom, and heating means positioned between the feeding chamber andthe injection cylinder in the direction of rotation of the turret whenmoving the material-receiving chambers from the feeding chamber to theinjection cylinder for heating plastic material in thematerial-receiving chambers when positioned adjacent said heating means.

9. A turret injection machine that includes in combination, an injectioncylinder providing an injection station, a feeding chamber providing afeeding station, a turret having a plurality of material-receivingchambers therein and rotatably disposed between said injection cylinderand said feeding chamber to transfer plastic material from the feedingchamber to the injection cylinder, plunger means for compressing plasticmaterial in said feeding chamber and for transferring the compressedmaterial into said material-receiving chambers in said turret, plungermeans associated with said injection cylinder for transferring plasticmaterial from said material-receiving chambers in said turret into saidinjection cylinder and to eject plastic material therefrom, andelectrode means adapted to be connected to a source of high frequencycurrent for establishing a eld of high frequency energy therebetween andwithin said material-receiving chambers in said turret and providing aheating station positioned between the feeding chamber and the injectionchamber for heating plastic material in the material-receiving chamberswhen positioned adjacent said heating means.

10. A turret injection machine that includes in combination, aninjection cylinder, a feeding chamber adjacent said injection cylinder,a turret rotatably disposed between said injection cylinder and saidfeeding chamber and having a plurality of material-receiving chambersmovable into" position adjacent said feeding chamber and into alignmentwith said injection cylinder, plunger means movable through saidmaterialreceiving chambers into said feeding chamber for compressingplastic material in the feeding chamber and for moving the compressedplastic material into a material-receiving chamber in the turret, meansfor establishing a eld of high frequency energy in saidmaterial-receiving chambers when said chambers are positioned betweensaid feeding chamber and said injection cylinder in the direction ofrotation of the turret from the feeding chamber to the injectioncylinder, and plunger means movable through said material-receivingchambers when in alignment with said injection cylinder for transferringheated and compressed plastic material from the material-receivingchamber in the turret into said injection cylinder and for producingpressure in the injection cylinder to eject the plastic materialtherefrom.

11. A turret injection machine that includes in combination, meansforming an injection station consisting of an injection cylinder and aninjection plunger co-operating therewith, means forming a feedingstation consisting of a feeding mechanism for feeding plastic material,a turret, means forming a heating station consisting of electrode meanspositioned in alignment on opposite sides of said turret, said turrethaving material-receiving chambers therein constructed of electricalinsulating material, said turret being rotatably disposed for indexingsaid chambers between said feeding station, said heating station andsaid injection station sequentially, and means for indexing said turret,said electrode means being adapted for connection to a source of highfrequency current when said turret is stationary for establishing afield of high frequency energy between the electrodes.

l2. A turret injection machine that includes in combination, aninjection cylinder, a turret having a plurality of material-receivingchambers, means adjacent said injection cylinder rotatably supportingsaid turret for positioning the material-receiving chambers thereof inalignment with said injection cylinder, a pre-compressing chamberdisposed adjacent said turret in alignment with one of saidmaterial-receiving chambers when another of the material-receivingchambers is in alignmentwith said injection cylinder, plunger meansImovable through a material-receiving chamber into said pre-compressingchamber forming an end wall thereof, a second plunger means movable insaid pre-compressing chamber to pre-compress plastic material betweenthe first and second plunger means and for moving the pre-compressedplastic material into the material-receiving chamber, and injectionplunger means movable through a material-receiving chamber to transferprecompressed plastic material therefrom into said injection cylinderand for producing pressure thereon to eject plastic material therefrom.

13. A turret injection machine that includes in combination, aninjection cylinder, a turret having a plurality of material-receivingchambers, means adjacent said injection cylinder rotatably supportingsaid turret for positioning the material-receiving chambers thereof inalignment with said injection cylinder, a pre-compressing-chamberdisposed adjacent said turret in alignment with one of saidmaterial-receiving chambers when another of the materialreceivingchambers is in alignment with said injection cy1inder, ,plunger meansmovable 17 through Aa material-receiving chamber into'v saidpre-compressing chamber forming an end wall thereof, a second plungermeans movable in said pre-compressing chamber to pre-compress plasticmaterial between the first and second plunger means and for moving thepre-'compressed plastic material into the material-receiving chamber,injection plunger means movable through a material-receiving chamber totransfer pre-compressed plastic material therefrom into said injectioncylinder and for producing pressure thereon to eject plastic materialtherefrom, said material-receiving chambers being constructed ofelectrical insulating material, and electrode means adapted to beconnected to a source of high .frequency current for establishing a eldof high frequency energy within'said materialreceiving chambers when-said chambers are positioned between said pre-compressing chamber andsaid injection cylinder in the direction of -rotation therebetween 14. Aturret injection machine that includes in combination, an injectioncylinder, a turret having a plurality of material-receiving chamberstherein, means disposed adjacent said injection cylinder for rotatablysupporting said turret to position said material-receiving chambers inalignment with said injection cylinder, a feeding chamber positionedrelative to said injection cylinder for alignment with one of saidmaterialreceiving chambers when another of the materialreceivingchambers is in alignment with said injection cylinder, wall meanspositioned adjacent said turret to retain plastic material within saidmaterial-receiving chambers while said turret is rotating from thefeeding chamber to the injection cylinder, and an injection plungerpositioned in alignment with said injection cylinder, said wall meanshaving an opening therethroughin alignment with the injection plunger,said injection plunger being movable into the injection cylinder throughsaid turret and said wall means for transfer of plastic material fromthematerial-receiving chamberinto said injection cylinder and forejection of plastic material from the injection cylinder. v

15. A turret injection machine that includes in combination, aninjection cylinder, a turret having -a plurality of material-receivingchambers therein, means disposed adjacent said injection cylinder forrotatably supporting said turret to position Vsaid material-receivingchambers in alignment with said injection cylinder, a feeding'chamberpositioned relative to said injection Ycylinder for alignment with oneof said materialreceiving chambers when another of the materialreceivingchambers is in alignment with said injection cylinder, wall meanspositioned adjacent said turret to retain plastic material within saidmaterial-receiving chambers' while said turret is rotating from thefeeding chamber to the injection cylinder, an injection plungerpositioned in alignment with said injection cylinder, said wall meanshaving an opening therethrough in alignment with the injection plunger,said injection plunger being movable into the injection cylinder throughsaid turret and said walls means for transfer of plastic material fromthe materialreceiving chamber into said injection cylinder and forejection of plastic material from the injection cylinder, and electrodemeans positioned adjacent opposite ends of said material-receivingchambers for establishing a eld of high frequency energy within saidmaterial-receiving chambers when the said chambers are positionedbetween the feeding chamber and the injection chamber in .thedirection-of rotation therebetween'. l

16. A turret injection machine that `includes in combination, aninjection cylinder, a turret having a plurality of material-receiivngchambers therein, means disposed adjacent said injection cylinder forrotatably supporting said turret'to position said material-receivingchambers in alignment with saidinjection cylinder, afeeding chamberpositioned relative to said injection cylinderv for alignment-with oneof said materialreceiving chambers whenanother of the material-receivingchambers is in alignment with said injection cylinder, wall meanspositioned adjacent said turret to retain plastic material within saidmaterial-receiving chambers while said turret is rotating from thefeeding chamber to the injection cylinder, an injection plungerpositioned in alignment' with .said injection cylinder said wallrmea'ns.having an opening therethrough in alignment with the injection plunger,said injection plunger being movable into the injectionv cylinderthrough saidv turret and said wall means for transfer of plasticmaterial from the Vmaterial-receiving chamber into said injection'cylinder yand for ejection of plastic material from the injectioncylinder, and electrode means positioned in said wall means and adaptedto be connected to a source of high frequency current for establishing afield of vhigh frequency energy within said `chambers when positionedbetween said feed chamber and said injection cylinderr in the directionof rotation therebetween.

l Vll. The structure set forth in claim 18 having electrode meanspositioned :in opposite ends of said materialY receiving chambers inthe'form of peripheral rings, contactl means in said wall means forengagement with said peripheral rings to thereby connect said electrodemeans with' a source of high frequency 'current when said materialreceiving chambers aredisposed between said feding chamber and 'saidinjection cylinder in the direction of rotation therebetween.

l118. A turret injection machine that includes in combination, aninjection cylinder, a turret having a plurality of `material-receivingchambers therein, means disposed adjacent said injection -cylinder forrotatably supporting said turret upon la horizontal axis to positionsaid materialreceiving 'chambers in alignment with said injectioncylinder, a feeding chamber positioned -relative -to said injectioncylinder for alignment with one of said material-receiving chambers whenanother of the material-receiving chambers is in alignment with saidinjection cylinder, wall means positioned adjacent both sides of saidturret to retain plastic material within said material-receivingchambers while said turret is rotating from the vfeeding chamber to theinjection cylinder, an injection plunger positioned in alignment withsaid injection cylinder, said wall means having an opening therethroughin alignment with the injection plunger, said injection plunger beingmovable into the injection cylinder through said turret and said wallmeansfor transfer of plastic material from the materialreceiivng chamberinto said injection cylinder and for ejection of plastic` material fromthe injection cylinder.4 l v' f 19. A turret injection machine thatincludes in combination, an injection cylinder, a turret' having aplurality of material-receiving 'chambers therein, means disposedadjacent said injection cylinder for` rotatably supporting said turretupon 19 avertical axis to position'said material-receiving chambers inalignment With'said injection'cylinder a feeding chamber positionedrelative to-said injection cylinder for Valignment with one of saidmaterial-receiving chambers' when another of the'material-receivingchambers is in alignment with said injection cylinder, wall meanspositioned adjacent the bottom side of said turret to retain plasticmaterial within said material-receiving chambers While s'aid turret isrotating from the feeding chamber tothe injection cylinder, andan'injection plunger positioned in alignment with said injectioncylinder, said wall means having an opening in alignment with theinjection plunger, said injection plunger being movable into theinjection cylinder through said turretl and said wall means for transferof plastic material from the material-receiving chamber into saidinjection cylinder and for ejection of plastic material from theinjection cylinder.

20. A turret injection machine vincluding Lin combination; an injectioncylinder, an injection plunger operably associated with said-cylindenjamould closing means, a turret rotatably disposed adjacent said cylinderhaving a plurality of ma- .terial-receiving chambers therein foralignment with the injection cylinder upon indexing of the turret, meansfor precompressing a charge of plastic material and for transferring theprecompressed charge into a material-receiving chamber in said turret,and f electrode -means adapted to be connected to a source of highfrequency current movable into engagement with plastic material inthematerial-receiving chambers of the turret for heating plastic materialtherein, means for unlatching said turret to permit rotation thereofincluding means responsive to the unlatching of the yturret foractuating means to index the turret, means responsive to lrotation ofsaid turret at the end of the indexing motion thereof for activating themeans for pre-,compressing a charge. of plastic material and the meansfor heating a chargeof plastic material, means for regulating theheating period of the plastic material and for reactivating the means tounlatch the turret upon completion of theV heating period for a secondindexing of the turret, and means responsive t liation of the turret oncompletion of the indexingmotion that is independent of the'tst somentioned means for activating theV means for clamping the mouldstogether, for reactivating the; means Vthat compresses the plasticmaterial-to cause operation thereof to insertthe'previously compressedplastic material into a materialfreceiving chamber in the turret, andfor activating the injection plunger fory ejecting plastic material fromthe injection cylinder.

21. A turret injection machine including in combination, an injectioncylinder, an injection plunger operably associated with said cylinder,a'mould closing means, aturret rotatably disposed adjacent Vsaidcylinder having a plurality of material-receiving chambers therein foralignment with the injection cylinder upon indexing of the turret, meansfor pre-compressing a charge of" plastic material'and for transferringthe precompressedy charge into a material-receiving chamber in saidturret, and electrode means adapted to be connected to a source ofl highfrequency current movable 'into engagement with plastic material inA thematerial-receiving chambers of the turret for heating plastic materialtherein, means for` unlatching said turret to permit rotation thereofincluding means responsive fi o to the unlatching of the turret foractuating means to index the turret, means responsive to yrotation ofsaid turret at the end'of the indexing motion thereof for activating themeans for pres compressing a charge of plastic material and the meansfor heating a charge of plastic material, means for regulating theheating period ofthe plastic material and for reactivating the means tounlatch the turret upon completion of the heating period for a secondindexing of the turret,- and means responsive to rotation of the turreton completion of the indexing motion that is independent of the'first somentioned means for activating'the means for Vclamping the molds to.-gether, for reactivating the meansk that com? presses the plasticmaterial to cause operation thereof to insert the'previously compressedplas.- tiematerial into a material-receiving chamber in the turret, andfor activating the injection plunger for ejecting plastic material from`the injection cylinder, and means-for regulating the period ofactivation of the injection plunger and forrfa-initiating operation ofthe mea-ns for un'.- latching theturret to restart another cycle ofoperation of the injection machine automatically.

422. A turret injection machine including in combination, an injectioncylinder, an injection plunger operably associated with said cylinder,va mould closing means, a turret rotatably disposed adjacent saidcylinder having a plurality offmaserial-receiving'chambers therein foralignment Withthe injection cylinder lupon indexing of the turret, meansfor pre-compressing'acharge' o f plastic material and fior transferringthe precompressed charge into amaterial-receiving chamber in saidturret, and electrode means adapted to be connected'to a sourceofhigh-ire.- quency current movable into engagement-With plasticmaterial in the material-receiving chambers of the turret for heatingplastic material therein, means for unlatching said turret to permitrotation thereof including means responsive to the unlatching of theturret for actuating means to index the turret, `means responsive torotation of said turret vat'the end ofthe index.- ing motion thereof foractivating the means for pre-,compressing a charge of plastic'materialand the means for heating a charge of plastic material, means forregulating the heating period` of the plastic material landYfor-vreactivating the means to unlatch the turretupoa completion O fthe heating period 'fora; second indexing ofthe turret, means responsiveto rotation of the turret on 'completion of the indemne motion thatisiadependent of the rstso mentioned means for activating the'means forclampingthe molds together, for reactivating the means 'that-com,-presses the plastic material to cause; Operation thereof to insert thepreviously @impressed-plastic material into amaterial-receivingchambetin the turret, and iorf-activatingthe injection pluri, eer foreiectng Yplastic material from the injection cylinder, means forresulatinatha period of, activation of the injection plungerand for'reinitiating operation of; the meansfor unlatching the turret torestart another cycle ofoperation of the ejection machineautomatically,` and means for vrendering-v said iast-mentioned meansinactive for restarting the, cycle of roperation'of the ma.v chine tothereby. place they same on a semi-auto# matic cycle'ofoperation.) Y 123. A turretV injection machine including in combination, an injectioncylinder, van injection plunger operablyassociated with 4said cylinder',a moldl closing means, a turret rotatably disposed adjacent saidcylinder having a plurality of material-receiving chambers therein foralignment lquency current movable into engagement with plastic materialin the material-receiving chambers of the turret for heating plasticmaterial therein, means Vlfor electrically -actuating the means forunlatching said turret to permit rotation thereol and including electricswitch means actuated by the unlatching of the latching'mechanism forinitiating operation of the means for indexing the turret, an electricswitch means actuated by rotation of the :turret upon completion of theindexing motion thereof for lactivating the means for compressing acharge of plastic material `and the means for heating the charge ofplastic material together with timing means for timing the heatingperiod, said timing means including means for reactivating the means forunlatching said turret to initiate a second indexing motion thereof,'and an electric switch means operated by movement of said turret uponcompletion `of the indexing motion thereof that is independent from thefirst of so mentioned means for activating the means for closing thermoulds, for reaotivating the means that compresses the plastic materialto cause operation thereof to insert the previously compressed lchargeof plastic material into a material-receiving chamber in the turret, andto activate the injection plunger so as to perform an injectionoperation.

24. A turret injection machine including in combination, an injectioncylinder, an injection plunger operably associated with said cylinder, amould closing means, a turret rotatably disposed adjacent said cylinderhaving a `plurality of material-receiving chambers therein for alignmentwith the injection cylinder upon indexing of the turret, means forpre-compressing a charge of plastic material and for transferring thepre-compressed charge into -a materialreceiving chamber in said turret,an electrode means adapted to be connected to a source of high frequencycurrent movable into engagement with plastic material in thematerial-receiving chambers of the turret for heating plastic materialtherein, means for electrically actuating the means for unlat-ching saidturret to permit rotation lthereof and including electric switch meansactuated by the unlatching of the latching mechanism for initiating themeans for indexing the turret, an electric switch means actuated byrotation of the turret upon completion of the indexing motion thereoffor activating the means for compressing a charge of plastic materialand the means for heating the charge of plastic material together withtiming means for timing the heating period, said timing means includingmeans for reactivating the means for unlatching said turret to initiatea second indexing motion thereof, an electric switch means operated bymovement of said turret upon completion of the indexing motion thereofthat is independent from the rst of so mentioned switch means foractivating the means for closing the molds, for reactivating the meansthat compresses the plastic material to cause operation thereof toinsert the previously compressed charge of plastic material into amaterial-receiving chamber in the turret,

andro activate the injee ion plunger .sc-astenerf'oi'm 'an injectionoperation, vand timingm'eans activated by 'the 'last-mentioned switchmeans for regulating the periodici fthe injection operation of theinjection plunger land for reactivating tial degree when placed in a eldof high frequency energy and rotatably mounted adjacent said injectioncylinder, means positioned between said injection station and saidfeeding station upon which said turret is rotatably mounted therebycarrying plastic material from the feeding station to the injectionstation, an injection plunger movable through said material-receivingchambers in said turret to transfer plastic material therefrom into saidinjection cylinder, and electrode means positioned in alignment onopposite sides of the turret for establishing a field of high frequencyenergy Within said materialreceiving chambers in said turret when saidchambers are in a stationary position between the feeding station andthe injection station.

26. A turret injection machine that includes in combination, aninjection cylinder, an intermittently movable metal turret rotatablymounted adjacent said injection cylinder and having a plurality ofmaterial-receiving chambers therein for sequential alignment with saidinjection cylinder, said material-receiving chambers in said turretbeing constructed of electrical insulating material that is not heatedreadily when in a field of high frequency energy, an injection plungermovable through said material-receiving chambers to transfer plasticmaterial from the chambers into the injection cylinder without placingthe chambers under any substantial pressure, a feeding mechanism forfeeding plastic material into said material-receiving chambers, andelectrode means disposed adjacent opposite ends of thematerial-receiving chambers and adapted to be connected to a source ofhigh frequency current when said material-receiving chambers arestationarily positioned between the feeding means and the injectingmeans upon indexing motion of the turret to thereby heat the plasticmaterial in the material-receiving chambers at a heating station beforetransfer thereof from the material-receiving chambers by the iniectionplunger upon indexing of the turret to place the material-receivingchamber in alignment with the injection cylinder.

27. A turret injection machine that includes in combination, aninjection cylinder providing an injection station, a plastic materialfeeding means disposed adjacent said injection cylinder forming afeeding station, electrode means adapted to be connected to a source ofhigh frequency current forming a heating station and disposed betweensaid feeding station and said injection station, a rotatable turrethaving metal Walls containing a plurality of materialreceiving chambersformed of electrical insulating material that is not readily heated whenin a field of high frequency energy and positioned e upon; said `turretso as 4to disposeJ a material-re- .ceiving ,chamber adjacent saidinjection station,

saidr feeding stationand said heating station simultaneously, means forcompressing a charge -of plastic'material at said feeding station for vsubsequentv heating at said` heating station upon being transferredthereto from the feeding station to the heating station, means forindexing the turret to sequentially yplacethe material-receiving`chambers atfthe feeding station, the

lheating, station and the injection station, and

means ,for ejecting plastic material from the .turret at the .injectionstation.

HOWARD F. MACMILLIN.,

RFEnENcEsoI'rED.

The following referenices 'are ofreeord inl the file of this patentzjv'f :UNITED STATES PATENTS n Date

